Breech plug for use with a muzzle-loading rifle

ABSTRACT

A breech plug for removable engagement with a muzzle-loading firearm barrel having a seating surface that forms an oblique angle with the longitudinal axis of the barrel. The breech plug includes a circumferential tightening mechanism. The circumferential tightening mechanism is configured to move the breech plug along the longitudinal axis within the firearm barrel. The breech plug also includes a continuous flange with a circumferential distal edge. The distal edge is configured to form a seal with the firearm barrel oblique angle seating surface upon movement of the breech plug by the circumferential tightening mechanism.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Non-Provisional patent application Ser. No. 12/469,232, filed May 20, 2009, the entirety of which is hereby incorporated herein by reference for all purposes.

TECHNICAL FIELD

The invention relates to a muzzle-loading rifle (also known as muzzleloader), i.e. a rifle in which the gunpowder and bullet are loaded and pressed into the barrel manually. More particularly, the invention has to do with the breech plug and the barrel of said rifle.

PRIOR ART

A muzzle-loading rifle is a rifle that, in structural and functional terms, replicates old-fashioned, traditional rifles and gives the user the feeling that they are firing an antique weapon in accordance with classical hunting techniques. Specifically, a muzzle-loading rifle is mainly characterised in that the gunpowder and the bullet must be manually inserted into the bottom of the barrel and pressed down before the shot can be fired.

After the gunpowder and the bullet have been pressed into the bottom of the barrel (next to the breech plug), the trigger is pulled, the shot happening as follows: the pulling of the trigger causes an ignition at the end of the breech plug opposite the gunpowder and the bullet. Said ignition travels through a relatively narrow internal conduit of the breech plug until it reaches the other side of the breech plug, reaching the gunpowder. The gunpowder then explodes, causing the bullet to be fired.

After a certain number of shots is performed using these rifles, traces of gunpowder usually collect in the connection area between the breech plug and the barrel (a connection area that is generally threaded although it may present other arrangements). These traces of gunpowder make it very difficult to detach the breech plug from the barrel, so much that in some cases it is impossible to detach the breech plug with the traditional tools the user carries with them. In more extreme cases it is impossible to remove the breech plug without damaging it, even when securing the rifle on work benches and using large levering tools. Bearing in mind that the breech plug must be detached from the barrel every day (so that it may be cleaned carefully in order to remove the traces of gunpowder and other impurities that may block the internal conduit), the difficulty or impossibility of separating both members can cause great inconvenience for the user.

Some solutions are known that attempt to solve this problem. One known solution consists of disposing of one or more elastic mechanized rings (shaped like a very closed C-shape, in other words almost in the form of a complete circle) between the breech plug and the barrel, on the end of the breech plug that is closer to the gunpowder and the bullet, with these rings acting as seals. These solutions may work for low-pressure explosions, but it has been found that they are ineffective with regard to the pressures generated in muzzle-loading rifles: muzzle-loading rifles are set up to use new-generation black gunpowder, which is much more powerful than the gunpowder used traditionally. Firstly, as the rings are not completely circular or closed, it has been found that gunpowder can pass through them and reach the connection area between the breech plug and the barrel. Secondly and above all, it has been found that in spite of the ring there is a small area between the breech plug and the barrel where particles of gunpowder are prone to collect. This space is large enough to cause a “sticking” effect that is just as problematic as the gunpowder reaching the connection area.

It is an objective of the invention to provide a design for a muzzle-loading rifle, more particularly for the rifle's breech plug and barrel, which prevents any gunpowder from passing from the gunpowder explosion area to the connection area between the breech plug and the barrel. Thus, the invention aims to facilitate the disconnection of the breech plug from the barrel as much as possible and enable said disconnection to be carried out manually without the help of any tools whatsoever.

BRIEF DESCRIPTION OF THE INVENTION

In order to achieve the aforementioned objectives the invention proposes a muzzle-loading rifle provided with a breech plug and a barrel, both of them fixed to each other in a connection area, wherein the breech plug comprises a first end further away from the part of the barrel where a bullet is to be housed and a second end closer to said part of the barrel. According to the invention, the second end of the breech plug is provided with a flange that presses internally against a seating surface of the barrel when the breech plug is fitted in the interior of the barrel. Said pressure increases when the gunpowder located near the second end of the breech plug explodes. In other words, the flange expands against the seating surface when the gunpowder explodes, increasing the pressure it exerts on the seating surface and therefore improving the sealing effect.

The flange of the breech plug is continuous, i.e. it does not have any breaks or gaps. Contact between the flange and the seating surface occurs in the area of 360° around the longitudinal axis of the breech plug. This is possible because the flange bends against the seating surface and may thus form a complete ring shape. The continuity enhances the barrier effect against the gunpowder and helps ensure the objectives of the invention are reached.

The invention provides a permanent seal between the breech plug and the barrel thanks to the pressure that the flange always exerts against the seating surface as a result of the breech plug being attached securely (for example, threaded tightly enough) to the barrel. And, above all, it is particularly interesting that because the pressure is exerted from the inside said sealing effect strengthens when the shot is fired, i.e., when the ignition and the powder explosion take place. Therefore, the invention allows achieving a non-constant, adaptive sealing between the breech plug and the barrel, said sealing being greatest when most needed: during the explosion and expansion of the gunpowder.

As a result, no gunpowder whatsoever is able to pass through to the connection area between the breech plug and the barrel (this has been tested in trials producing results that were in fact surprising). The effect is so positive that the breech plug may be manually and softly detached after several shots, with no effort at all.

According to a first example embodiment, the invention is a breech plug for removable engagement with a muzzle-loading firearm barrel having a seating surface that forms an oblique angle with the longitudinal axis of the barrel. The breech plug includes a circumferential tightening mechanism. The circumferential tightening mechanism is configured to move the breech plug along the longitudinal axis within the firearm barrel. The breech plug also includes a continuous flange with a circumferential distal edge. The distal edge is configured to form a seal with the firearm barrel oblique angle seating surface upon movement of the breech plug by the circumferential tightening mechanism.

According to a second example embodiment, the invention is a breech plug for removable engagement with a muzzle-loading firearm barrel having a seating surface that forms an oblique angle with respect to the longitudinal axis of the barrel. The breech plug includes a continuous flange with a circumferential distal edge. The distal edge is configured to contact the firearm barrel seating surface. The breech plug also includes a tightening mechanism that is configured to move the circumferential distal edge toward the firearm barrel seating surface. The tightening mechanism has a unitary construction with the continuous flange. And, movement caused by the tightening mechanism after the circumferential distal edge contacts the firearm barrel seating surface increases the pressure between the circumferential distal edge and the firearm barrel seating surface.

According to a third example embodiment, the invention is a muzzle-loading firearm including a barrel with a longitudinal axis and a seating surface that forms an oblique angle with respect to the longitudinal axis. The muzzle-loading firearm also includes a continuous flange with a circumferential distal edge. The distal edge is configured to contact an internal position along the firearm barrel seating surface. The muzzle-loading fire arm also includes a circumferential tightening mechanism that is configured to move the circumferential distal edge toward the firearm barrel seating surface. The circumferential tightening mechanism has a unitary construction with the continuous flange. And, movement caused by the circumferential tightening mechanism after the circumferential distal edge contacts the firearm barrel seating surface increases the pressure between the circumferential distal edge and the firearm barrel seating surface.

In another aspect, the invention relates to a breech plug for a muzzle-loading firearm. The breech plug preferably includes a threaded connection area having threads for engagement with a barrel of a muzzle-loading firearm, the threaded connection area defining an outside thread diameter. The breech plug preferably also includes an expanded gripping surface positioned at first end of the breech plug, the expanded gripping surface having an external diameter greater than the outside thread diameter of the threaded connection area. The breech plug preferably also includes a deformable, continuous circumferential sealing flange projecting axially forward from a second end of the breech plug opposite the threaded connection area from the expanded gripping surface, the sealing flange defining a flange diameter less than the outside thread diameter of the threaded connection area. The breech plug preferably also includes an internal conduit extending through the breech plug from the first end to the second end.

BRIEF DESCRIPTION OF THE DRAWINGS

Details of the invention can be seen in the accompanying non-limiting figures.

FIG. 1 shows a cross-section of a conventional muzzle-loading rifle, in particular the area of the rifle in which the breech plug is located inside the barrel.

FIG. 2 shows a cross-section of an embodiment of the invention.

FIG. 3 shows an enlarged view of the area of FIG. 2 where the flange and the seating surface come into contact.

FIG. 4 shows a perspective view of the breech plug used in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a cross-section of a conventional muzzle-loading rifle, in particular the area of the rifle in which the breech plug 1 is located inside the barrel 2. In the rifle shown in the figure the breech plug 1 is fixed to the barrel 2 by means of a threaded connection area 3. The breech plug 1 comprises a first end 4 and a second end 5. A bullet 6 is also shown housed inside the barrel 2 in front of a certain amount of gunpowder 7. As seen, the first end 4 is the end of the breech plug 1 further from the bullet 6, whereas the second end 5 is the end closer to the bullet 6.

In the rifle shown in the figure the shot occurs as follows. Firstly, an ignition occurs in the chamber 8 in the first end 4 of the breech plug 1. Said ignition travels along an internal conduit 9 of the breech plug 1 until it reaches the second end 5 of the breech plug 1. When the ignition reaches the gunpowder 7 an explosion occurs, causing the bullet 6 to be fired in the shot direction D. The explosion of the gunpowder 7 also results in some traces of gunpowder being projected through gaps between the outer walls of the breech plug 1 and the inner walls of the barrel 2 towards the connection area 3, potentially blocking it. To prevent this some manufacturers provide the rifle with an elastic mechanized ring 10 that acts as a seal between the area where the gunpowder 7 is located and the connection area 3. It has been found that this elastic mechanized ring 10—and other similar solutions using seals—largely prevent the passage of gunpowder to the connection area 3. However, in this and other similar solutions it has been found that the gunpowder collects in a small area 15 between the breech plug 1 and the barrel 2, which is sufficiently large to cause a “sticking” effect that is just as problematic as the gunpowder reaching the connection area 3.

FIG. 2 shows a similar view to that of FIG. 1, in this case showing an embodiment of the invention. The rifle shown in the figure also comprises a breech plug 1 and a barrel 2, fixed to each other in a connection area 3. In the rifle according to the invention, the second end 5 of the breech plug 1 is provided with a flange 11 that presses against a seating surface 12 of the barrel 2 when the breech plug 1 is fitted inside the barrel 2. In other words, in the case of the figure where the connection area 3 is threaded, when the breech plug is threaded 1 into the barrel 2 the flange 11 is pressed and tightened against said seating surface 12, creating a seal between both parts 1, 2. The flange 11 of the breech plug 1 is continuous along its full perimeter.

The flange 11 presses internally on the seating surface 12, as shown in FIGS. 2 and 3. In other words, the flange 11 is closer to the longitudinal axis 13 than the seating surface 12. A very interesting third effect is achieved with this: when the shot is fired, the high pressures generated inside the barrel 2 push the flange 11 against the seating surface 12 in its whole perimeter. As a result, the seal is strengthened in the moment when it is most needed, i.e. when the gunpowder explodes 7.

Preferably, the seating surface 12 on which the flange 11 presses forms an angle other than 90° with the longitudinal axis 13. This embodiment has been proven to multiply (supposing a constant torque setting) the normal force during the explosion between the seating surface 12 and the flange 11 by three. This performance (the sealing effect that does not allow gunpowder to pass) will be optimum the smaller the contact area between the flange 11 and the seating surface 12, because the smaller the contact area, the greater the pressure between the surfaces (supposing a constant normal force).

To ensure that the invention works correctly, it has been found that the flange 11 should have a reduced thickness, the aim being to guarantee a minimum flexibility (if it were completely rigid, it would not be tensioned and a seal would not be created, or alternatively the breech plug 1 would have to be screwed on very tightly to make it sufficiently tensioned, something that the user would find almost impossible). In consequence, the breech plug 1 preferably also comprises 14 a protective projection disposed externally to the flange 11 to protect the flange 11 from being damaged and possibly broken when the user is handling the breech plug while detaching the barrel. Said protective projection 14 is preferably an outer wall concentric to the flange, as shown in FIGS. 2 and 3.

FIG. 4 shows a perspective view of the breech plug 1 used in FIG. 2. As can be seen, the flange 11 is continuous along the entire 360° around the longitudinal axis 13. The reduced thickness of the flange 11 can also be seen. As a result, it is interesting that the flange 11 is exteriorly protected by the protective projection 14.

The present invention provides for other embodiments different to those shown. For example, the connection between the breech plug 1 and the barrel 2 can be other than the threaded connection shown in the figures. 

1. A breech plug for removable engagement with a muzzle-loading firearm barrel having a seating surface that forms an oblique angle with the longitudinal axis of the barrel, the breech plug comprising: a circumferential tightening mechanism, the circumferential tightening mechanism configured to move the breech plug along the longitudinal axis within the firearm barrel; and a continuous flange comprising a circumferential distal edge, the distal edge configured to form a seal with the firearm barrel oblique angle seating surface upon movement of the breech plug by the circumferential tightening mechanism.
 2. The breech plug of claim 1, wherein the circumferential tightening mechanism comprises a threaded surface.
 3. The breech plug of claim 2, wherein the circumferential tightening mechanism further comprises a handle.
 4. The breech plug of claim 2, wherein the diameter of the circumferential tightening mechanism is greater than the diameter of the circumferential distal edge.
 5. The breech plug of claim 1, wherein the circumferential tightening mechanism is unitarily constructed with the continuous flange.
 6. The breech plug of claim 1, wherein the circumferential tightening mechanism is configured to move the continuous flange distal edge to a position beyond the firearm barrel seating surface.
 7. The breech plug of claim 6, wherein movement caused by the circumferential tightening mechanism after the circumferential distal edge contacts the firearm barrel seating surface increases the pressure between the circumferential distal edge and the firearm barrel seating surface.
 8. The breech plug of claim 6, wherein the circumferential distal edge is configured to form a seal with an internal position along the firearm barrel seating surface.
 9. A breech plug for removable engagement with a muzzle-loading firearm barrel having a seating surface that forms an oblique angle with respect to the longitudinal axis of the barrel, the breech plug comprising: a continuous flange comprising a circumferential distal edge, the distal edge configured to contact the firearm barrel seating surface; and a tightening mechanism configured to move the circumferential distal edge toward the firearm barrel seating surface, the tightening mechanism having unitary construction with the continuous flange, and movement caused by the tightening mechanism after the circumferential distal edge contacts the firearm barrel seating surface increases the pressure between the circumferential distal edge and the firearm barrel seating surface.
 10. The breech plug of claim 9, wherein the tightening mechanism comprises a circumferential surface having a greater diameter than the circumferential distal edge.
 11. The breech plug of claim 10, wherein the tightening mechanism circumferential surface comprises a threaded surface.
 12. The breech plug of claim 9, wherein the tightening mechanism is configured to move the continuous flange distal edge to a position beyond the firearm barrel seating surface.
 13. The breech plug of claim 9, wherein the circumferential distal edge is configured to form a seal with an internal position along the firearm barrel seating surface.
 14. A muzzle-loading firearm comprising: a barrel comprising a longitudinal axis and a seating surface that forms an oblique angle with respect to the longitudinal axis; a continuous flange comprising a circumferential distal edge, the distal edge configured to contact an internal position along the firearm barrel seating surface; and a circumferential tightening mechanism configured to move the circumferential distal edge toward the firearm barrel seating surface, the circumferential tightening mechanism having unitary construction with the continuous flange, and movement caused by the circumferential tightening mechanism after the circumferential distal edge contacts the firearm barrel seating surface increases the pressure between the circumferential distal edge and the firearm barrel seating surface.
 15. The muzzle-loading firearm of claim 12, wherein the circumferential tightening mechanism comprises a handle.
 16. The muzzle-loading firearm of claim 12, wherein the circumferential tightening mechanism comprises a threaded surface.
 17. The muzzle-loading firearm of claim 12, wherein the circumferential tightening mechanism comprises a diameter greater than the continuous flange distal edge.
 18. A breech plug for a muzzle-loading firearm comprising: a threaded connection area having threads for engagement with a barrel of a muzzle-loading firearm, the threaded connection area defining an outside thread diameter; an expanded gripping surface positioned at first end of the breech plug, the expanded gripping surface having an external diameter greater than the outside thread diameter of the threaded connection area; a deformable, continuous circumferential sealing flange projecting axially forward from a second end of the breech plug opposite the threaded connection area from the expanded gripping surface, the sealing flange defining a flange diameter less than the outside thread diameter of the threaded connection area; and an internal conduit extending through the breech plug from the first end to the second end.
 19. The breech plug of claim 16, comprising a unitary integral component.
 20. The breech plug of claim 16, further comprising a protective projection concentric with and externally positioned relative to the circumferential sealing flange.
 21. The breech plug of claim 16, wherein the expanded gripping surface comprises raised and recessed surface features. 